Human Health Criteria

Human health ambient water quality criteria are numeric values limiting the amount of chemicals present in our nation's waters. These human health criteria are developed under Section 304(a) of the Clean Water Act of 1972.

Water quality criteria are developed by assessing the relationship between pollutants and their effect on human health and the environment. These criteria are used by states and Indian tribes to establish water quality standards and ultimately provide a basis for controlling discharges or releases of pollutants.

A human health criterion is the highest concentration of a pollutant in water that is not expected to pose a significant risk to human health.